Washington D.C. · August
Run in the pre-dawn.
Average high is 85°F with a 69°F overnight low. Expect 17 rain days — plan around the radar. Humid heat punishes mid-morning — get out before sunrise for the only truly comfortable window.
Avg high / low
85° / 69°F
Humidity
74%
Rain days
17/mo
Wind
8 mph
What August feels like in Washington D.C.
Sunrise
06:23
Mid-month average
Sunset
20:01
Mid-month average
Time-of-day breakdown
Morning
Coolest, driest air of the day. The window before sunrise is the most reliable comfortable hour.
Midday
Heat peaks here. Skip unless you've got shade and pace tolerance.
Evening
Cools off after sunset but still warm. Good for easy efforts; avoid hard intervals if you're chasing pace.
What to wear running in Washington D.C. in August
The kit for August in Washington D.C.: light, breathable, and moisture-wicking — singlet or short-sleeve only, a water-resistant cap or jacket on standby.
August vs the surrounding months
vs July
-2° avg high
-2 rain days
Washington D.C. in July →
August
85°F avg high
17 rain days
Best: pre-dawn
vs September
+6° avg high
+3 rain days
Washington D.C. in September →
Frequently Asked Questions
What is the best time of day to run in Washington D.C. in August?+
Pre-dawn. Humid heat punishes mid-morning — get out before sunrise for the only truly comfortable window.
What's the average temperature in Washington D.C. in August?+
Average high 85°F, average low 69°F.
How does August compare to surrounding months in Washington D.C.?+
Compared to July (avg high 88°F), August is cooler. Compared to September (avg high 80°F), August is warmer.
Does it rain often in Washington D.C. in August?+
Expect about 17 measurable rain days in August, on average.